Carrier route record
AABZN→ORD
American Airlines · Bozeman to Chicago
- Flights
- 467
- Period
- July 2025 to June 2026
- Share of route
- 37%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on BZN to ORD draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 467 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.6%, so American on BZN to ORD runs 12 points behind the country as a whole. Across a thousand flights that is about 124 extra late arrivals.
Key figures
On time
65.2%
Arrivals under 15 minutes late, of 460 completed flights
Avg delay
105 min
Across delayed arrivals only, not all flights
Cancelled
0.64%
National rate is 1.81%
Whole route
73.5%
Every carrier on BZN to ORD, 1,255 flights
These figures cover 467 flights between July 2025 and June 2026. Beyond the headline rate, 15.2% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
American against every carrier on BZN to ORD
American flew 467 of the 1,255 flights on BZN to ORD, about 37% of it. Its 65.2% on time is 8 points worse than the route as a whole, which runs 73.5%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from United at 79.7% to American at 65.2%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 658 | 79.7% | 79 min | 1.52% | B |
| Envoy Airthin sample | 41 | 75.6% | 71 min | 0.00% | B+ |
| SkyWest Airlinesthin sample | 89 | 70.8% | 57 min | 0.00% | C+ |
| American Airlines (this page) | 467 | 65.2% | 105 min | 0.64% | C+ |
Departure window
When American runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am64 flights85.7%
- 8am–11am—
- 11am–2pm271 flights58.1%
- 2pm–5pm74 flights70.3%
- 5pm–8pm58 flights69.0%
- 8pm–5am—
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 58.1% on time against 85.7% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 11am–2pm window is the busiest, with 271 flights scheduled in it.
Across the year
American on BZN to ORD through the year
July is the worst month at 51.7% on time, 25 points below February, the best at 76.6%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 61 flights.
Across the week, Tuesday is the strongest day at 72.5% on time and Friday the weakest at 59.2%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why American runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 17,000 reported delay minutes.
- 41%Late-arriving aircraft
- 30%Carrier
- 20%National Airspace System
- 9%Extreme weather
- 0%Security
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 17,000 reported delay minutes here, that single category outweighs weather by 5 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 16,769 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 85.7% on time here.
Cancellations are rare at 0.64%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 15.2% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 1,185 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 64.0% on time across 468 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 467 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking American on BZN to ORD
Put together: treat all of this as provisional. 467 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 65.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 460 completed flights over 12 months sit behind that.
Related
Where to go next
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.